ES2767081T3 - Method for catalytic conversion of keto acids by dimeric keto acid intermediate and hydrocarbon hydrotreating - Google Patents

Abstract

A method for increasing the molecular weight of a keto acid, the method comprising the steps of providing a reactor with a raw material comprising at least one keto acid represented by Scheme 1 below and subjecting the raw material to a first CC coupling reaction or reactions in the presence of an ion exchange resin catalyst to produce at least one dimeric keto acid, provide a reactor with a starting material comprising the at least one dimeric keto acid, subject the starting material to a second reaction or CC coupling reactions to a temperature of at least 200 ° C; ** Formula ** where, in Scheme 1, n and m are whole numbers independently selected from each other from the list consisting of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

Description

DESCRIPTION

Method for catalytic conversion of keto acids by dimeric keto acid intermediate and hydrocarbon hydrotreating

Technical field

The present invention relates to the catalytic conversion of keto acids, including methods of increasing the molecular weight of keto acids, products obtainable by such methods, as well as the use of such products for the production of liquid hydrocarbons and / or gasoline or diesel fuel or oil-based components.

Prior art

The production of hydrocarbons used as fuel or base oil components and chemical compounds from biomass is of increasing interest since they are produced from a sustainable source of organic compounds.

Kev acid levulinic acid (LA, 4-oxopentanoic acid) is one of the many platform molecules that can be derived from biomass. They can be produced from pentoses and hexoses of lignocellulosic material (see Figure 1) at relatively low cost. Some of the advantages and disadvantages of using levulinic acid as a platform molecule relate to the fact that it is considered as a reactive molecule due to its keto and acid functionality.

Levulinic acid esters have been suggested as fuel components, and also as cold flow additives for diesel fuels, and in particular methyl and ethyl esters have been used as additives in diesel fuel. Gamma-valerolactone (GVL), which can be obtained by reducing levulinic acid, has been used as a fuel additive in gasoline. A further reduction of GVL to 2-methyltetrahydrofuran (MTHF) provides a product that can be combined with gasoline by up to 60%. Alkyl valerates produced from levulinic acid have also been suggested as biofuels.

Levulinic acid has also been used in the production of liquid hydrocarbon fuels through numerous catalytic routes, including a method of producing a distribution of alkenes, centered the distribution around C12, which involves converting an aqueous solution of GVL into a first reactor system. in butenes, followed by oligomerization in a second reactor over an acid catalyst (eg Amberlyst® 70).

Serrano-Ruiz et al. (Appl. Catal., B, 2010, 100, 184) that produces a Cg-ketone (5-nonanone) by reduction of levulinic acid to GVL in a Ru / C catalyst in a reactor followed by reaction of 40% by weight of GVL in water and H2SO40.02 M in a double bed arrangement of Pd / Nb2O5 ceria-zirconia at 325-425 ° C, 14 bars (1.4 MPa), WHSV = 0.8-0.5 h '1 in another reactor.

US 2006/0135793 A1 (ex Blessing and Petrus) disclose the dimerization of levulinic acid to a C10 unit in the presence of hydrogen, with a strongly acidic heterogeneous catalyst, eg, an ion exchange resin catalyst.

WO 2006/056591 A1 discloses a process for the dimerization of levulinic acid.

Summary of the invention

The enhancement of levulinic acid and other keto acids to higher molecular weight compounds can be achieved through reaction pathways involving one or more reaction steps, both of which have certain advantages and disadvantages. The use of a single reactor compared to multiple reactors can be advantageous because the number of processes is reduced and therefore the economy of the process is improved. Some of the drawbacks associated with enhancement pathways, for example, through the use of individual reactors, and that these reactions generate highly reactive intermediates with more than one functional group, which can further react with other unwanted molecules resulting in deactivation of the catalyst. Suppression of side reactions usually results in lower yield of desired products due to lower temperatures, dilute reagent solutions, or less reactive catalysts. Accordingly, an indirect improvement route of a raw material using multiple reactors or multiple catalyst beds in a single reactor may be preferred, in some situations, compared to a direct improvement route.

Therefore, there is a need for additional processes for upgrading levulinic acid and other keto acids to higher molecular weight compounds, which are suitable for use as, for example, fuel or oil-based components or as components in the production of fuels or components based on oil or chemical substances. In particular, there is a need for such additional processes, which reduce the processing costs by, for example, improving the performance of the desired components or chemicals and / or reducing the total catalyst consumption by improving the useful life of the catalyst.

The present invention was practiced in view of the prior art described above, and one of the objectives of the present invention is to provide methods that allow the improvement of keto acids by improved routes to achieve higher molecular weight compounds.

Another objective of the present invention is to provide the improvement of keto acids to higher molecular weight compounds with good performance and low processing cost.

The inventors of the present invention have discovered that the challenges related to the formation of reactive intermediates and catalyst deactivation can be alleviated by selective conversion of keto acids to dimeric keto acids in the presence of an ion exchange resin catalyst and the subsequent conversion of dimeric keto acids by CC coupling reactions to higher molecular weight compounds at temperatures of 200 ° C or higher.

Dimeric keto acids obtained by C-C coupling reactions in the presence of an ion exchange resin catalyst (RIE) have also been found to be especially suitable for conversion to higher molecular weight compounds by C-C coupling reactions. Without intending to impose any theory, the RIE catalyst is considered to catalyze the aldol condensation reactions of levulinic acid by producing levulinic acid dimers comprising two carboxylic acid groups. The presence of carboxylic acid groups in the levulinic acid dimers obtained with the RIE catalyst makes them strongly reactive at temperatures above 200 ° C.

The higher molecular weight components produced by the method of the invention are suitable for use, for example, as fuel or oil-based components or chemicals, or as fuel production components or oil-based components or chemicals.

Therefore, the present invention provides a method of increasing the molecular weight of a keto acid as defined in claim 1.

In the step of subjecting the starting material to one or more secondary CC coupling reactions, the at least one dimeric keto acid undergoes at least one CC coupling reaction with another dimeric keto acid, derived from dimeric keto acid, keto acid or keto acid derivative present in the starting material so as to increase the molecular weight of the dimeric keto acid. The dimeric keto acids participating in the C-C coupling reaction may be of the same type (have the same chemical formula) or of a different type. The dimeric keto acid derivative includes all of the compounds that can be obtained directly from the dimeric keto acid by C-C coupling reactions or other reactions such as lactonization and dehydroxylation. Examples of dimeric keto acids according to the invention are shown in the following formulas, using levulinic acid dimers as an example:

Examples of dimeric keto acid derivatives according to the invention are shown in the following formulas, using levulinic acid dimers as an example:

The keto acid derivative includes all the compounds that can be obtained directly from a keto acid by C-C coupling reactions or lactonization and dehydroxylation. Keto acid derivatives can be selected from the list consisting of lactones and lactone derivatives of keto acids, and pentanoic acid.

In the one or more secondary C-C coupling reactions, the at least one dimeric keto acid reacts with other reagents with the formation of a new carbon-carbon bond in the product. In other words, the molecular weight of the dimeric keto acid is increased by using the dimeric keto acid as a direct precursor (one-step reaction) and within a single reactor or single catalyst bed. Naturally, subsequent C-C coupling reactions can occur to further increase the molecular weight of the product of the C-C coupling reaction. Preferably, these additional reactions are carried out in the same (single) reactor or catalyst bed.

The at least one dimeric keto acid is preferably a dimer of a Y-keto acid, more preferably a dimer of levulinic acid. The at least one dimeric keto acid can be a mixture of different dimer keto acids. Preferably, the first and second C-C coupling reactions are performed in a first and second reactor, respectively. In this regard, it is noted that the term "a reactor" of the present invention refers to a reaction vessel, which may comprise one or more catalyst beds or a single catalyst bed within the reaction vessel comprising one or more catalyst beds.

Accordingly, the method of the present invention is a two-step method in which, firstly, a dimeric keto acid is produced, and then the produced dimeric keto acid is further subjected to the second C-C coupling reaction. The two steps of the present invention are not carried out as a reaction in a single vessel, that is, not in the same reaction liquid at the same time. Instead, the reactions are separated in space and / or time, that is, spatially and / or chronologically. That is, the two-stage reaction does not encompass the production of the (temporary) intermediate of the dimeric keto acids that are immediately further subjected to the second CC coupling reaction, but rather the first CC coupling reaction is carried out, then the reaction conditions are changed (eg, by increasing the temperature of the reaction liquid and / or by bringing the reaction liquid to a different reactor or to a different part of a flow reactor), and then the second reaction is carried out DC coupling.

The first and second reactors used in the method of the present invention can be a flow reactor, preferably a continuous flow reactor. Alternatively, the first and / or second reactor may be a batch reactor, preferably with stirring. One type of flow reactor is preferred from the standpoint of production efficiency. More preferably, the second C-C coupling reaction is carried out downstream of the first C-C coupling reaction. When a flow reactor is used, the catalyst system is preferably immobilized within the reactor.

The second C-C coupling reaction or reactions are preferably carried out in concentrated solutions of dimeric keto acids in the starting material. Preferably, the content of the at least one dimeric keto acid in the starting material is at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight, even more preferably at least 55 % by weight, and even more preferably at least 60% by weight. If multiple dimeric keto acids are present in the starting material, the "content of the at least one dimeric keto acid" refers to the total content of all dimeric keto acids.

In this regard, it should be noted that, in the present invention, the term "starting material" includes all material fed into the reactor, except for the material that constitutes the catalyst system, if present. Therefore, the calculation of the content of the at least one dimeric keto acid in the starting material does not consider the amount of catalyst if the reaction is carried out in the presence of a catalyst.

The use of concentrated solutions of dimeric keto acids allows a high probability of the C-C coupling reactions between two dimeric keto acids, thus providing a high yield of the desired products and low amounts of secondary products. The solvent in the (concentrated) solution can be any keto acid or dimeric keto acid. In addition, water and / or organic solvents can be used.

The water content in the starting material is preferably less than 10.0% by weight, and more preferably less than 5.0% by weight and even more preferably less than 2.0% by weight. The calculation of the water content in the starting material does not take into account the amount of catalyst, if present. The first C-C coupling reaction (s) of keto acids in the presence of the ion exchange resin catalyst is known to occur to at least some extent through aldol condensation reactions, in which water is formed. The water formed during the first C-C coupling reactions in the first reactor can be removed at least partially by providing the starting material to the second reactor.

In the step of subjecting the raw material to one or more first DC coupling reactions, the at least one Keto acid undergoes at least one CC coupling reaction with another keto acid or keto acid derivative present in the raw material such that a dimeric keto acid is produced. Keto acids that participate in the CC coupling reaction may be of the same type and have the same chemical formula or of a different type. In the first CC coupling reaction, the at least one keto acid reacts with another keto acid or keto acid derivative with the formation of a new carbon-carbon bond in the product. In other words, the molecular weight of the keto acid is increased by using the keto acid as a direct precursor (one-step reaction) and within a single reactor or single catalyst bed.

Preferably, the at least one keto acid in the raw material is a Y-keto acid, preferably levulinic acid. Preferably, the average pore diameter of the ion exchange resin catalyst in the range of 150A-300 A, preferably 200-250 A. The average pore diameter of the ion exchange resin catalyst can be measured with the BET method, that measures the isothermal adsorption of nitrogen (ASTM D-3663-03 (2008)). The specific surface is generally determined by the BET method, which measures the isothermal adsorption of nitrogen (ASTM D-3663-03 (2008)).

Preferably, the raw material is subjected to a first C-C coupling reaction or reactions at a temperature of 100-190 ° C, preferably 120-160 ° C, more preferably 120-140 ° C. This temperature range has been found to be especially suitable for obtaining a high yield of the dimeric keto acids suitable for use as the at least one dimeric keto acid in the next method step.

It has also been found that the stability of the ion exchange catalyst and the performance of the dimers can be improved if the raw material undergoes DC coupling reactions in the presence of hydrogen and if the ion exchange resin catalyst comprises a hydrogenation metal . Preferably, the hydrogenation metal is selected from the group consisting of Ni, Mo, Co, Ru, Rh, Pd, Pt, or a combination thereof.

The starting material can be subjected to second C-C coupling reactions in the presence of a catalyst or without a catalyst, in which case, the second C-C coupling reactions are carried out by thermal reactions. Thermal reactions are favorable from an economic point of view, since carrying out the C-C coupling reactions without catalyst reduces the process costs and increases the economic viability of the process.

The inventors have also discovered that the starting material can be subjected to the second coupling C-C in the presence of a solid metal oxide catalyst system, which preferably comprises a first metal oxide and a second metal oxide. The catalyst system comprising a first metal oxide and a second metal oxide is suitable for catalyzing multiple types of C-C coupling reactions of dimeric keto acids that allow the production of higher molecular weight compounds of keto acids with good performance and in a single reactor.

Selection between a second catalytic and non-catalytic C-C coupling reaction depends on the type of product compounds desired. Thermal reactions of dimeric keto acids have been found to produce a wide variety of C-C coupling reaction products that are suitable for use as fuel components, oil-based components, and chemicals. The catalytic C-C coupling reactions of dimeric keto acids have been found to produce a somewhat narrower product distribution, which is also suitable for use as fuel components, oil-based components, and chemicals.

Preferably, the solid metal oxide catalyst system comprises a mixture of the first metal oxide and the second metal oxide.

The catalyst system preferably has a specific surface area of 10 to 500 m2 / g. The specific surface is generally determined by the BET method, which measures the isothermal adsorption of nitrogen (ASTM D-3663).

In the present invention, the metal oxide mixture includes a mixture of individual metal oxide materials, for example, in powder form, mixed metal oxides, where the metal oxides form a common matrix, and supported metal oxides, where the metal oxide more active is deposited on the metal oxide that acts as a carrier.

Various methods can be used to prepare mixtures of metal oxides. In the preparation of mixed metal oxides, the metal oxide precursors can be brought together from a gas phase or liquid solution before being transformed into oxides. In the preparation of supported metal oxides, a metal oxide can be brought from the gas phase or liquid solution to the surface of a solid support in the form of oxide (or hydroxide) before the transformation of the metal oxide precursor into its form. oxide.

Preferably, the solid metal oxide catalyst system comprises a first metal oxide supported on a second metal oxide as a carrier.

Preferably, the surface density of the metal atoms of the first metal oxide supported on the second metal oxide is 0.5 to 20 metal atoms / nm2. The surface density of the metal atoms of the first metal oxide of the catalyst system is calculated based on the content. of metal oxide of the catalyst and the specific surface area of the catalyst system. For example, the K2O / TO2 catalyst used in the invention has a K2O content of 2.4% by weight and the catalyst has a specific surface area of X [m2 / g], therefore the density of K atoms is (2 * 0.024 [g / g] / 94.2 [g / mol]) * 6,022 * 1023 [atoms / mol] / X [m2 / g] * 1018 [nm2 / m2] (if X = 100 m2 / g) = 3 , 06 atoms / nm2

There are various metal oxides that can be used in the catalyst system to catalyze the C-C coupling reactions of dimeric keto acids. Preferably, the first metal oxide comprises an oxide of one of K, Li, Be, B, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Sr, Y, Zr, Nb, Mo, Ba, W, Pb, Bi, La, Ce, Th, and the second metal oxide comprises an oxide of one of K, Li, Be, B, Na, Mg, Al , Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Sr, Y, Zr, Nb, Mo, Ba, W, Pb, Bi, La, Ce, Th or a combination thereof, the first metal oxide not being the same as the second metal oxide.

Preferably, the first metal oxide comprises an oxide of one of K, Li, Be, B, Na, Mg, Al, Si, Ca, Sr, and Ba and the second metal oxide comprises an oxide of one of Ti, Sc, V , Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Sr, Y, Zr, Nb, Mo, Ba, W, Pb, Bi, La, Ce, Th, or a combination thereof.

Preferably, the catalyst system comprises potassium oxide as the first metal oxide and titanium oxide as the second metal oxide.

Preferably, the content of the first metal oxide of the catalyst system is from 1.0 to 40.0% by weight, preferably from 2.0 to 30.0% by weight, preferably in addition to 13.0 to 30.0% by weight , calculated by weight of the metal oxide with respect to the total mass of the catalyst. The metal oxide content is determined by measuring the metal content in the catalyst and calculating the content of the metal oxide in which the metal is present with the highest oxidation number, if there are multiple (stable) oxides of a metal.

Preferably, the starting material further comprises at least one keto acid, preferably a y-keto acid, more preferably levulinic acid.

The reactivity of dimeric keto acids in thermal or catalytic C-C coupling reactions has been found to be enhanced by the addition of more reactive forms of the keto acids (i.e. monomers) to the starting material. Preferably, the content of the at least one keto acid in the starting material is at least 1.0% by weight, preferably at least 5.0% by weight, more preferably at least 10.0% by weight, or at minus 20.0% by weight. If multiple types of keto acids are present in the starting material, the "content of the at least one keto acid" refers to the total content of all keto acids (excluding dimeric keto acids and other oligomeric keto acids).

Preferably, the weight ratio of the at least one keto acid contained to the at least one dimeric keto acid contained in the starting material is in the range of 1: 5 to 10: 1, preferably 1: 3 to 5: 1.

Preferably, the starting material is introduced into the reactor in the liquid phase, as opposed to, for example, the gas phase. One of the advantages of introducing the starting material into the liquid phase reactor is that it is not necessary to heat the product to prepare a gas stream. Furthermore, the presence of solid components in the starting material can lead to clogging of the catalyst. Therefore, it is preferred that the starting material is in the liquid phase and that it does not include a considerable amount of solid material, for example less than 4.0% by weight, preferably less than 1.0% by weight, more preferably less than 0.2% by weight of solid material. Herein, the solid material includes solid material suspended or dispersed in a liquid phase.

The CC coupling reaction (s) can be controlled by adjusting various parameters, including the selection of reaction conditions such as: temperature, pressure, and hourly and mass-based space velocity (WHSV) (kg of starting material or raw materials / kg of catalyst per hour).

Preferably, the second CC coupling reaction or reactions are performed at a temperature that is at least 10 ° C, more preferably at least 20 ° C, additionally preferably at least 40 ° C greater than the temperature used in the first CC coupling reaction .

The second reaction or CC coupling reactions to increase the molecular weight of the dimeric keto acids are preferably performed at a temperature of 200-400 ° C, preferably 210-300 ° C, more preferably 220-280 ° C, and even more preferably 220- 260 ° C. This temperature range has been found to be especially suitable for obtaining a high degree of reaction products comprising more than two ketoacid units (C13-C30) while avoiding excessive polymerization and coking of the catalyst.

Preferably, the second reaction or CC coupling reactions are carried out at a pressure of 0.5-100 bar (0.05-10 MPa), preferably 1.0-50 bar (0.1-5 MPa), more preferably 1 0-20 bar (0.1-2 MPa).

The second CC coupling reactions, when a catalyst is used, are preferably performed at a time and mass space velocity of 0.05 I r 1 to 2.0 I r 1, preferably 0.1 I r 1 to 1 , 8 I r 1, more preferably 0.2 I r 1 to 1.5 I r 1, most preferably 0.25 I r 1 to 1.25 I r 1. WHSV affects the composition of the resulting material, since it determines the effective contact time between the reagent and the catalyst. The aforementioned ranges have been shown to provide a high degree of favorable products.

The second reaction or C-C coupling reactions can be performed in the presence of hydrogen. In this case, the iiidrogen is fed to the reactor as part of the starting material. It is also possible to carry out the second C-C coupling reaction (s) in the absence of hydrogen hydrogen and to recover the catalyst by adding hydrogen hydrogen to the reaction mixture from time to time.

The second CC coupling reactions can be carried out in a starting matter (H2 / liquid starting material) reaction of 100-3000 Nl / l, preferably 200-2000 Nl / l, more preferably 500-1800 Nl / l most preferably 500-1500 Nl / l. Herein, liquid starting material refers to starting material, which is predominantly in liquid form under the reaction conditions.

If the CC coupling reaction or reactions are carried out in the presence of hydrogen hydrogen, the metal oxide catalyst system may also comprise at least one hydrogenation metal selected from Group VIII of the Periodic Table of Elements, preferably Co, Ni, Ru, RIi , Pd, and Pt.

The second C-C coupling reaction or reactions can be carried out under a stream of nitrogen. It was discovered that the nitrogen stream entrains the water and CO2 formed in the reactions, thus improving the product yield. Preferably, the nitrogen starting matter rate (N2 / liquid starting material) is 100-3000 Nl / l, preferably 200-2000 Nl / l, more preferably 500-1800 Nl / l and most preferably 500-1500 Nl / l. The combined use of iiidrogen and nitrogen seems to provide especially favorable results.

The characteristics of the starting material dimers depend on the method used to produce the dimers. Preferably, the at least one dimeric keto acid is selected from a group of 4-iihydroxy-4-methyl-6-oxononanedioic acid, 3-acetyl-4-hydroxy-4-methylheptanedioic acid, 5- (2-methyl-5- oxotetraiiidrofuran-2-yl) -4-oxopentanoic, (E) -4-methyl-6-oxonon-4-enodioic acid, 4-hydroxy-6-methylnonanodioic acid, (E) -6-iihydroxy-4-methylnon- 4-enodioic, (Z) -3-acetyl-4-methyliiept-3-enodioic acid, 3- (3-acetyl-2-methyl-5-oxotetraiiidrofuran-2-yl) propanoic acid, (Z) -3- acid 1 (1-iihydroxyethyl) -4-methyliiept-3-enodioic, 3- (1-hydroxyethyl) -4-methylheptanedioic acid or a combination thereof.

In another aspect of the present invention, there is provided a method of producing ii-hydrocarbons from a raw material comprising at least one keto acid.

In summary, the present invention relates to a method of increasing the molecular weight of a keto acid, the method comprising the steps of providing a reactor with a raw material comprising at least one keto acid and subjecting the raw material to a first reaction. or CC coupling reactions in the presence of an ion exchange resin catalyst to produce at least one dimeric keto acid, providing a reactor with a starting material comprising the at least one dimeric keto acid, subjecting the starting material to a second reaction or reactions DC coupling at a temperature of at least 200 ° C. The keto acid is represented by Scheme 1 below:

Scheme 1

In Scheme 1, n and m are integers independently selected from each other from the list consisting of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

In the present invention, it is further preferred that the at least one dimeric keto acid is a dimer of a Y-keto acid, preferably a levulinic acid dimer.

In the present invention, it is further preferred that the first and second CC coupling reactions or reactions are performed in first and second reactors, respectively.

In the present invention, it is further preferred that the content of the at least one dimeric keto acid in the starting material is at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight, even more preferably at least 55% by weight, and even more preferably at least 60% by weight.

In the present invention, it is further preferred that the water content in the starting material is less than 15.0% by weight, preferably less than 10.0% by weight, more preferably less than 5.0% by weight.

In the present invention, it is further preferred that the at least one keto acid in the raw material is a Y-keto acid, preferably levulinic acid.

In the present invention, it is further preferred that the average pore diameter of the ion exchange resin catalyst is in the range of 150-300 A, preferably 200-250 A.

In the present invention, it is further preferred that the first C-C coupling reaction or reactions are performed at a temperature in the range of 100-190 ° C, preferably 120-160 ° C, more preferably 120-140 ° C.

In the present invention, it is further preferred that the feedstock undergo the first C-C coupling reaction (s) in the presence of hydrogen.

In the present invention, It is further preferred that the ion exchange resin catalyst comprises at least one hydrogenation metal selected from Group VIII of the Periodic Table of the Elements, preferably Co, Ni, Ru, Rh, Pd, and Pt, more preferably Pd.

In the present invention, it is further preferred that the starting material is subjected to the second coupling C-C in the absence of catalyst.

In the present invention, it is further preferred that the starting material is subjected to the second C-C coupling reaction (s) in the presence of a solid metal oxide catalyst system comprising a first metal oxide and the second metal oxide.

In the present invention, it is further preferred that the catalyst system have a specific surface area of 10 to 500 m2 / g.

In the present invention, it is further preferred that the solid catalyst system comprises a mixture in which the first metal oxide is supported on the second metal oxide.

In the present invention, it is further preferred that the surface density of the metal atoms of the first metal oxide supported on the second metal oxide is 0.5 to 20 metal atoms / nm2

In the present invention, it is further preferred that the first metal oxide comprises an oxide of one of K, Li, Be, B, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co , Ni, Cu, Zn, Br, Sr, Y, Zr, Nb, Mo, Ba, W, Pb, Bi, La, Ce, Th and the second metal oxide comprises one of K, Li, Be, B, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Sr, Y, Zr, Nb, Mo, Ba, W, Pb, Bi, La, Ce, Th, or a combination thereof, the first metal oxide not being the same as the second metal oxide.

In the present invention, it is further preferred that the first metal oxide comprises a potassium oxide and the second metal oxide comprise a titanium oxide.

In the present invention, it is further preferred that the first metal oxide comprises a tungsten or cerium oxide and the second metal oxide comprise a zirconium, titanium, silicon, vanadium or chromium oxide, preferably a zirconium or titanium oxide.

In the present invention, it is further preferred that the content of the first metal oxide of the catalyst system is 1.0 to 40.0% by weight, preferably 2.0 to 30.0% by weight, more preferably 13.0 at 30.0% by weight, calculated on the weight of metal oxide with respect to the total mass of the catalyst.

In the present invention, it is further preferred that the starting material further comprise a keto acid, preferably a Y-keto acid, more preferably levulinic acid.

In the present invention, it is further preferred that the content of the at least one keto acid in the starting material is at least 1.0% by weight, preferably at least 5.0% by weight, more preferably at least 10.0% by weight, or at least 30.0% by weight.

In the present invention, it is further preferred that the weight ratio of the at least one keto acid contained in the al minus one dimeric keto acid contained in the starting material [keto acid: dimeric keto acid] is in the range of 1: 5 to 10: 1, preferably 1: 3 to 5: 1.

In the present invention, it is further preferred that the starting material is introduced into the reactor in the liquid phase.

In the present invention, it is further preferred that the second C-C coupling reaction (s) be carried out at a temperature in the range of 200-400 ° C, preferably 210-300 ° C, more preferably

220-280 ° C, and most preferably 220-260 ° C.

In the present invention, it is further preferred that the second CC coupling reaction (s) be carried out at a pressure in the range of 0.5-150 bar (0.05-0.5 MPa), preferably 1.0-50 bars (0.1-5 MPa), more preferably 1.0-20 bars (0.1-2 MPa).

In the present invention, it is further preferred that the second C-C coupling reaction (s) be performed at a space velocity based on time and mass (kg starting material / kg catalyst * h) in the range of 0.05 Ir1 to

2.0 h-1, preferably 0.1 Ir1 to 1.8 h-1, more preferably 0.2 Ir1 to 1.5 h-1, with 0.25 h-1 to 1.25 h'1 .

In the present invention, it is further preferred that the starting material comprises at least one 4-hydroxy-4-methyl-6-oxononanodioic acid, 3-acetyl-4-hydroxy-4methylheptanedioic acid, 5- (2-methyl-5-acid -oxotetrahydrofuran-2-yl) -4-oxopentanoic acid, (E) -4-methyl-6-oxonon-4-enodioic acid, 4-hydroxy-6-methylnonanodioic acid, (E) -6-hydroxy-4-methyl acid -non-4-enodioic, (Z) -3-acetyl-4- methylhept-3-enodioic acid, 3- (3-acetyl-2-methyl-5-oxotetrahydrofuran-2-yl) propanoic acid, (Z) acid -3-1 (1-hydroxyethyl) -4-methylhept-3-enodioic and 3- (1-hydroxyethyl) -4-methylheptanedioic acid.

The present invention also further relates to a method of producing hydrocarbons, the method comprising steps to increase the molecular weight of a keto acid represented by Scheme 1 above using the method described above to obtain a reaction product and subject the reaction product to a hydrodeoxygenation step and, optionally, an isomerization step.

Brief description of the drawings

Figure 1 shows a schematic illustrating the conversion of lignocellulosic material to levulinic acid.

Figure 2 shows a schematic illustrating some reaction products of some levulinic acid dimers. The figure is not intended to cover all reaction products of levulinic acid dimers, nor is it intended to show all types of levulinic acid dimers. Figure 2 illustrates possible C-C coupling reactions of levulinic acid dimers by ketone and an aldol condensation reaction.

Figure 3 shows an overview of a possible scheme for further improvement of the products obtained by the C-C coupling reactions.

Figure 4 shows an overview of a possible scheme for the preparation and further improvement of the products obtained by the C-C coupling reactions.

Detailed description of the invention

One of the challenges in increasing the molecular weight of keto acids by C-C coupling reactions is the high reactivity of the intermediates, which results in too high a degree of oligomerization of the starting components.

The inventors have discovered that oligomerization of a keto acid, specifically levulinic acid, in the presence of a solid base catalyst such as K2O / TO2 results in the formation of large amounts of coke and tar, which poison the catalyst by blocking the reactive sites in the catalyst surface and ultimately result in reactor clogging. Without intending to impose any theory, it is suggested that this occurs due to reactions of levulinic acid to produce more reactive precursors, such as angelica lactones, known to have a high tendency to polymerize at temperatures above 200 ° C.

The inventors have also discovered that oligomerization of levulinic acid in the presence of an ion exchange resin catalyst such as Amberlyst 70 results in the formation of levulinic acid dimers, but the performance of higher molecular weight products such as trimers. , tetramers and pentamers of levulinic acid is still very low. One of the reasons for the poor performance of the Amberlyst catalyst in the formation of higher molecular weight compounds is the need for relatively low reaction temperatures since the ion exchange catalyst tends to degrade at temperatures above 200 ° C.

The first attempt was made to reduce unwanted polymerization reactions and to control the reactions of polymerization of levulinic acid by carrying out the K2O / TÍO2 catalyzed reactions in dilute aqueous solutions. The addition of water to suppress coking reactions, however, turned out to also decrease the performance of the catalyst system resulting in low performance of the desired oligomerization products.

The invention is based on the surprising finding that the molecular weight of keto acids could be increased by selective production of dimeric keto acids in the presence of an ion exchange resin catalyst and subsequent oligomerization of dimeric keto acids to higher molecular weight compounds. high at a temperature of at least 200 ° C. Without intending to impose any theory, it is suggested that dimeric keto acids are less prone to the formation of reactive intermediates at temperatures above 200 ° C and this allows the molecular weight of dimeric keto acids to be increased by means of DC coupling reactions while Significantly reduces the formation of coke and tar and other unwanted polymerization products.

The inventors have also discovered that the ion exchange resin catalyst is especially suitable for the production of some types of dimeric keto acids, which can be converted to trimeric, tetrameric, hexameric and heptameric keto acids at a temperature of at least 200 ° C.

Accordingly, one aspect of the present invention is a method of increasing the molecular weight of a keto acid as defined in claim 1.

The present invention also relates to a method of increasing the molecular weight of keto acids.

Keto acids are organic molecules that have both a keto function (> C = O) and a carboxylic acid (COOH) or carboxylate (COO-) function. In the present specification, specific forms of keto acids include embodiments where the keto function is an aldehyde (-CH = O).

The keto acid can be an alpha-keto acid (such as pyruvic acid), beta-keto acid (such as acetoacetic acid), gamma-keto acid (such as levulinic acid), or delta-keto acid. The keto acid has a keto functionality and a carboxylic acid functionality.

Scheme 1

Scheme 1 illustrates keto acids according to the present invention, where n and m are integers independently selected from each other from the list consisting of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 , 10. The keto acid is preferably a gamma keto acid, more preferably levulinic acid (m = 2, n = 0).

A dimeric keto acid refers herein to a product of a dimerization reaction, in which two keto acid molecules are coupled to each other by a C-C coupling reaction.

Preferably, it can be determined that more than 15% by weight of the reaction product of the reaction belongs to the group containing products of trimerization, tetramerization, pentamerization and hexamerization of the keto acid. By trimerization, tetramerization, pentamerization and hexamerization products are meant products related to three, four, five and six molecules of one or more keto acid units that are coupled to each other, respectively. Reactions can occur between dimeric keto acids or between keto acids and dimeric keto acids as shown in Figure 2. Typically, most other reaction products (ie excluding trimerization, tetramerization, pentamerization and hexamerization products of the keto acid) correspond to non-reactive material.

In the case of a starting material comprising keto acid derivatives in addition to dimeric keto acids and keto acids, the trimerization, tetramerization, pentamerization and hexamerization products may additionally contain mixed CC coupling products comprising one or more keto acid units and / or derivatives thereof.

In the present invention, the molecular weight of keto acids and dimeric keto acids is increased by one or more types of CC coupling reactions. Many types of DC coupling reactions are known in the art, and the person skilled in the art will be able to identify such DC coupling reactions according to the reaction conditions provided. In particular, the CC coupling reactions can be ketone reactions or reactions that occur through an enol or enolate intermediate. Preferably, the CC coupling reactions are selected from the list comprising: aldol-type reactions and condensations, ketones, reactions where the CC coupling involves an alkene, as well as other oligomerization reactions. CC coupling reactions can occur between two identical molecules or it can be a cross reaction between two different molecules.

The at least one dimeric keto acid preferably contains a dimeric Y-keto acid, more preferably a levulinic acid dimer. In addition, one or more additional dimeric keto acids can be used.

Preferably, the first and second C-C coupling reactions are performed in a first and second reactor, respectively.

Preferably, the starting material comprises as a major component one or more dimeric keto acids, for example, in some embodiments, the content of the at least one dimeric keto acid in the starting material is at least 30% by weight such as at least 40 % by weight, at least 50% by weight, at least 55% by weight or at least 60% by weight.

Preferably, the water content in the starting material is less than 5.0% by weight, preferably less than 2.0% by weight, more preferably less than 1.0% by weight. In some embodiments, no water is present in the starting material, but internal water may be produced in some of the condensation reactions.

The conversion of the dimeric keto acids to the desired C-C coupling reaction products has been found to increase as the content of dimeric keto acid in the starting material increases. The presence of water has been found to decrease the reactions of keto acids to produce coke precursors, but the addition of water also decreases the activity of the catalyst and the yield of the products of the C-C coupling reaction decreases. The performance of C-C coupling products must be high enough to allow an economically viable process to be produced for the production of fuel components and chemicals from keto acids.

In addition to dimeric keto acids, the starting material may also contain aldehydes, such as furfural or hydroxymethyl-furfural.

In the step of subjecting the raw material to one or more first DC coupling reactions, the at least one keto acid undergoes at least one DC coupling reaction with another keto acid or keto acid derivative present in the raw material such that a keto acid is produced dimeric.

The ion exchange catalyst has been found to be especially suitable for obtaining high grade dimeric keto acids, which can be upgraded to higher molecular weight components in the presence of a solid base catalyst system.

Preferably, the at least one keto acid in the raw material is a Y-keto acid, preferably levulinic acid. The reactivity of an RIE catalyst with a particular reagent is determined by the average pore diameter of the catalyst. Preferably, the average pore diameter of the ion exchange resin catalyst is in the range of 150-300 A, preferably 200-250 A.

Preferably, the raw material is subjected to a first C-C coupling reaction or reactions at a temperature of 100-190 ° C, preferably 120-160 ° C, more preferably 120-140 ° C. This temperature range has been found to be especially suitable for obtaining a high yield of dimeric keto acids suitable for use as the at least one dimeric keto acid in the second C-C coupling reactions.

It has also been found that the stability of the ion exchange catalyst and the performance of the dimers can be improved if the raw material undergoes DC coupling reactions in the presence of hydrogen and if the ion exchange resin catalyst comprises a hydrogenation metal . Preferably, the ion exchange resin catalyst comprises a hydrogenation metal selected from the group of Ni, Mo, Co, Ru, Rh, Pd, Pt, or a combination thereof.

A solid metal oxide catalyst system comprising a first and a second metal oxide has been found to catalyze multiple types of C-C coupling reactions between dimeric keto acids and keto acid monomers and to simultaneously suppress the coking tendency of reaction intermediates.

The reactivity of a catalyst depends on the number of active sites on the catalyst surface and on the specific surface of the catalyst. According to one embodiment, the solid base catalyst has a specific surface area of 10 to 500 m2 / g. The catalyst system having a specific surface area in said range has been shown to provide sufficient reactivity with the dimeric keto acids to obtain a high yield of the desired CC coupling reaction products such as trimers, tetramers, pentamers, hexamers and heptamers of a keto acid but at the same time minimizing the reactions of the keto acids with coke precursors.

Preferably, the first metal oxide comprises an oxide of one of K, Li, Be, B, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Sr, Y, Zr, Nb, Mo, Ba, W, Pb, Bi, La, Ce, Th, and the second metal oxide comprises an oxide of one of K, Li, Be, B, Na, Mg, Al , Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Sr, Y, Zr, Nb, Mo, Ba, W, Pb, Bi, La, Ce, Th or a combination thereof, the first metal oxide not being the same as the second metal oxide. Combinations of metal oxides include mixtures of individual metal oxides (solid solutions), mixed metal oxides, and supported metal oxides.

Preferably, the first metal oxide comprises an oxide of one of K, W, Li, Be, B, Na, Mg, Al, Si, Ca, Sr, and Ba and the second metal oxide comprises an oxide of one of Ti, Sc , V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Sr, Y, Zr, Nb, Mo, Ba, W, Pb, Bi, La, Ce, Th, or a combination thereof.

These oxides have been shown to provide good reaction properties to catalyze the second C-C couplings. Additionally, it has been found that the above mentioned carriers show good transport properties without altering the operation of the most active part, including a synergistic interaction. Also, the aforementioned combinations allow the catalyst to be used for a prolonged period of time without deterioration and / or dissolution in the acidic reaction medium and, therefore, allow an overall reduced consumption of the catalyst.

Preferably, the first metal oxide comprises potassium oxide and the second metal oxide comprises titanium oxide, the potassium oxide preferably being supported on a titanium oxide carrier.

Preferably, the catalyst system comprises tungsten oxide or ceria supported on a metal oxide carrier, wherein the carrier is preferably selected from the group consisting of zirconia, titania, silica, vanadium oxide, chromium oxide, preferably zirconia or titania.

It has been suggested that second C-C coupling reactions in the presence of K2O / TO2 occur by ketone reactions, in which reactions the molecular weight of the dimeric keto acid is increased and a significant amount of oxygen is simultaneously removed. The loss of oxygen in the second coupling DC is favorable for the production of hydrocarbons from keto acids because the removal of oxygen in a hydrodeoxygenation stage consumes a large amount of hydrogen, which increases the cost of the process and also reduces the reduction of CO2 emissions in the case of using hydrogen produced from fossil raw material. Furthermore, it has been found that the keto groups formed in the second C-C coupling reactions can be easily hydrotreated, allowing the use of lower reaction temperatures during the hydrodeoxygenation step. The use of lower hydrodeoxygenation temperatures also decreases the cyclization tendency of C-C coupling products.

Preferably, the content of the first metal oxide of the catalyst system is from 1.0 to 40.0% by weight, preferably from 2.0 to 30.0% by weight, preferably in addition to 13.0 to 30.0% by weight , calculated by weight of the metal oxide with respect to the total mass of the catalyst. Preferably, the starting material further comprises at least one keto acid, preferably a Y-keto acid, more preferably levulinic acid.

Preferably, the content of the at least one keto acid in the starting material is at least 1.0% by weight, preferably at least 5.0% by weight, more preferably at least 10.0% by weight, or at minus 30.0% by weight.

Preferably, the weight ratio of the content of the at least one keto acid to the content of the at least one dimeric keto acid in the starting material is in the range of 1: 5 to 10: 1, preferably 1: 3 to 5: 1.

Preferably, the starting material comprises a mixture of a dimeric keto acid together with derivatives of dimeric keto acids, such as at least 30% by weight of dimeric keto acid and at least 10% by weight of one or more derivatives of dimeric keto acids, based in the total mass of the starting material.

Preferably, the starting material is fed to a single reactor, or to a single reactor bed. The reactor must be able to pressurize, and accept both the starting material and the catalyst system, if present. The reactor shall have means, such as one or more inlets and / or outlets, for supplying gases and for adding / removing starting material. Furthermore, means for controlling temperature or pressure and temperature are preferably present.

Reaction temperature has been found to have a significant effect on product distribution. At temperatures below 200 ° C, the performance of the DC coupling products of dimeric keto acids in the second reaction or CC coupling reactions is too low and at temperatures above 400 ° C, the performance may decrease due to coke formation and other unwanted polymerization products. It is preferred that the second reaction or CC coupling reactions are preferably carried out at a temperature in the range of 200-400 ° C, more preferably 210-300 ° C, even more preferably 220-280 ° C and even more preferably 220-260 ° C. The aforementioned temperature ranges have been found to be especially suitable for obtaining a high degree of reaction products comprising more than two ketoacid units (C13-C30) while avoiding excessive polymerization and coking of the catalyst.

Since most C-C coupling seconds are produced in the liquid phase, pressure and temperature are appropriately selected to keep the reagents in the liquid phase. According to one embodiment, the CC coupling reaction (s) is performed at a pressure of 0.5-100.0 bar (0.05-10.0 MPa), preferably 1.0-50 bar (0.1- 5 MPa), more preferably 1.0-20 bar (0.1-2 MPa).

Preferably, the second CC couplings are performed at a space velocity based on hour and mass (kg of starting material / kg of catalyst * hour) of 0.05 I r 1 to 2.0 I r 1, preferably 0, 1 I r 1 to 1.8 I r 1, more preferably 0.2 I r 1 to 1.5 I r 1, most preferably 0.25 I r 1 to 1.25 I r 1. WHSV affects the composition of the resulting material, since it determines the effective contact time between the reagent and the catalyst. The aforementioned ranges have been shown to provide a high degree of favorable products.

The second C-C coupling reaction (s) can occur in the presence of hydrogen. The thiidrogen can be mixed with one or more other gases, preferably an inert gas such as nitrogen, argon, thiellium or another of the noble gases, or gas that behaves inertly under the reaction conditions of the present invention. By behaving inertly, it is considered that the gas should not participate to a considerable extent as a reaction element and, preferably, the inert gas should participate as little as possible, such as not participating at all. The addition of thiidrogen will usually not introduce hydrogenation activity unless the solid metal oxide catalyst system comprises a hydrogenation metal, but it is proposed to modify the surface properties of the reducible metal oxide that is part of the catalyst system.

Preferably, the second coupling CC is carried out with a flow rate (H2 / starting material) of 100-3000 Nl / l, preferably 200-2000 Nl / l, more preferably 500-1800 Nl / l and most preferably 500-1500 Nl / l. Preferably, the nitrogen starting matter rate (N2 / liquid starting material) is 100-3000 Nl / l, preferably 200-2000 Nl / l, more preferably 500-1800 Nl / l and most preferably 500-1500 Nl / l. The combined use of hydrogen and nitrogen appears to provide especially favorable results.

Preferably, the solid metal oxide catalyst system comprises a hydrogenation metal in addition to the first and second metal oxides. The hydrogenation metal is preferably selected from Ru, RIi, Pd and Pt or a combination thereof. It was discovered that a catalyst system comprising a hydrogenation metal further increases the stability of the catalyst and suppresses the oligomerization reactions of the dimeric keto acids to give components unsuitable for use as fuel components or chemicals.

Preferably, the at least one dimeric keto acid is selected from a group of 4-iihydroxy-4-methyl-6-oxononanedioic acid, 3-acetyl-4-hydroxy-4-methylheptanedioic acid, 5- (2-methyl-5- oxotetraiiidrofuran-2-yl) -4-oxopentanoic acid, (E) -4-methyl-6-oxonon-4-enodioic acid, 4-hydroxy-6-methylnonanodioic acid, (E) -6-iihydroxy-4-methylnon- 4-enodioic, (Z) -3-acetyl-4-methyliept-3-enodioic acid, 3- (3-acetyl-2-methyl-5-oxotetraiiidrofuran-2-yl) propanoic acid, (Z) -3- 1 (1-iihydroxyethyl) -4-methyliiept-3-enodioic, 3- (1-hydroxyethyl) -4-methylheptanedioic acid or a combination thereof.

The raw material can be obtained from the processing of lignocellulosic material, and said processed material can be used directly or can be purified to various degrees before being used as a raw material in the method of the present invention. Levulinic acid can be produced by, for example, the Biofine method disclosed in US5608105.

In another aspect of the present invention, there is provided the reaction product which can be obtained by the method according to the present invention. This product can be used directly as fuel or oil-based components or chemicals or as intermediates in the production of fuel or oil-based components or chemicals.

The reaction product that can be obtained by the method herein can be subjected - if additionally desired - to a hydrogen peroxide (HDO) step to remove oxygen, which, in some embodiments, produces completely deoxygenated material (i.e., hydrocarbon compounds that do not have oxygen atoms). The produced hydrocarbons can be used as fuel or oil-based components or chemicals or as starting materials in the production of fuel or oil-based components or chemicals. The hydroxy-oxygenated products can also be further isomerized to produce, for example, isoparaffins.

One of the advantages of the present invention is that keto acids produced from renewable materials are they can improve to higher molecular weight hydrocarbons and / or hydrocarbon derivatives, which can be used as fuel or oil-based components or chemicals or as starting materials in the production of fuel or oil-based components or chemicals.

Reaction products from the first and / or second CC coupling reactions can be fractionated to remove potentially unreacted keto acid monomers and other light components such as water and CO2 formed during the first and second CC coupling reactions from the Reaction products, as illustrated in Figure 3. Fractionation can be carried out by any conventional means such as distillation. The unreacted keto acid monomer can optionally be recirculated and combined with the starting material into the first reactor.

Another aspect of the present invention involves a method of producing hydrocarbons, the method comprising steps for increasing the molecular weight of a keto acid using the method of the present invention to obtain a reaction product and subjecting the reaction product to a hydrodeoxygenation step and , optionally, to an isomerization step.

Preferably, the HDO catalyst used in the hydrodeoxygenation step comprises a hydrogenation metal on a support, such as, for example, an HDO catalyst selected from a group consisting of Pd, Pt, Ni, Co, Mo, Ru, Rh, W or any combination thereof. The hydrodeoxygenation step can be carried out, for example, at a temperature of 100-500 ° C and at a pressure of 10-150 bar (1-15 MPa). Water and light gases can be separated from the HDO product by any conventional means such as distillation. After removal of water and light gases, the HDO product can be fractionated into one or more fractions suitable for use as gasoline, jet fuel, diesel, or oil-based components. Fractionation can be carried out by any conventional means, such as distillation. Optionally, a part of the product from the HDO stage can be recirculated and combined with the starting material into the HDO reactor.

Another aspect of the present invention involves a hydrocarbon composition that can be obtained by the method according to the present invention. This product can be used as fuel or oil-based components or chemicals or as intermediates in the production of fuel or oil-based components or chemicals.

The product of the hydrodeoxygenation step can also be subjected to an isomerization step in the presence of hydrogen and an isomerization catalyst. Both the hydrodeoxygenation step and the isomerization step can be carried out in the same reactor. In some embodiments, the isomerization catalyst is a bifunctional noble metal catalyst, for example Pt-SAPO or a Pt-ZSM catalyst. The isomerization step can be carried out, for example, at a temperature of 200-400 ° C and at a pressure of 20-150 bar (2 15 MPa).

It is preferred that only a part of the HDO product is subjected to an isomerization step, in particular, the part of the HDO product that is subjected to isomerization may be the heavy fraction with a boiling point at or above a temperature of 300 ° C.

The hydrocarbon product that can be used as fuel or oil-based components or chemicals or as intermediates in the production of fuel or oil-based components or chemicals.

In general, the choice of subjecting the HDO product to isomerization largely depends on the desired properties of the final products. If the HDO product contains a large amount of n-paraffins, the HDO product can be subjected to an isomerization step to convert at least part of the n-paraffins to isoparaffins to improve the cold properties of the final product.

Examples

materials

As example catalysts, the Amberlyst CH 28 catalyst, the K2O / TO2 catalyst and the WO3 / ZrO2 catalyst were used in the first and second CC coupling reactions of levulinic acid and levulinic acid dimers, respectively. K2O / TO2 catalyst is available from BASF and WO3 / ZrO2 catalyst is available from Saint-Gobain NORPRO. The composition of the K2O / TO2 catalyst is shown in Table 1.

Table 1. Composition of

K2O / TÍO2 catalyst

The WO3 / ZrO2 catalyst (type SZ 6 * 143) has a surface area of 130 m2 / g and a WO3 content of 18% by weight calculated based on the total mass of the catalyst. The Amberlyst CH 28 catalyst is a Pd-doped ion exchange resin catalyst having an average pore diameter of 260 A and a Pd content of 0.7% by weight.

The specific surface area and tungsten oxide content of the WO3 / ZrO2 catalyst and the average pore diameter of the RIE Amberlyst CH 28 catalyst were provided by the catalyst manufacturers.

Example 1

Increased molecular weight of levulinic acid dimers by second C-C coupling reactions with catalyst system K ^two O / TiO ^two

The performance of the K2O / TiO2 catalyst was evaluated in a reactor test cycle with a starting material comprising 43 parts by weight of levulinic acid and 55 parts by weight of levulinic acid dimers and 2 parts by weight of acid oligomers levulinic.

The starting material was obtained by reacting commercial grade levulinic acid (97% by weight) in the presence of the catalyst Amberlyst CH 28 (trade name; Pd-doped ion exchange resin) at a temperature of 130 ° C, pressure of 20 bar (2 MPa), WHSV of 0.2 h-1 and ratio of hydrogen to raw material of 1350 Nl / l. The starting material was prepared in a tubular reactor. 2 wt% H2O was also added continuously to stabilize catalyst activity. The WHSV and the relationship between hydrogen and organic material were calculated from the amount of liquid raw material fed to the reactor.

The second DC coupling reactions for the starting material were carried out in a continuous tubular fixed bed reactor at temperatures ranging from about 220 ° C to about 250 ° C and under a pressure of about 1 bar (0.1 MPa) , using an hourly and mass-based space velocity (WHSV) of 0.7 h-1. Reactions were carried out with a stream of nitrogen (10 l / h) to study the effect of hydrogen added to the starting material. WHSV was calculated from the amount of monomers, dimers, and oligomers (= liquid starting material) fed into the reaction vessel.

For the reactions at different conditions, the amount of gas formed was determined from the liquid yield (gas = 100 - liquid product). The liquid product consists of the organic phase that includes the water formed during the reaction.

The quantitative amount of LA in the liquid product was determined by HPLC analysis. The relative amount of dimers and oligomers in the organic phase was obtained from GPC chromatograms. The composition of the organic phase, - including unreacted LA, was calculated with respect to the liquid product.

The product yield and liquid phase compositions for the conversion of levulinic acid over the K2O / TO2 catalyst system in a nitrogen stream are presented in Tables 2 and 3.

T l 2. niinrrn imi nrnl liz r K2 Ti 2.

Table 3. Distribution of products in the organic phase with the K ² O / TÍO ² catalyst determined according to the li P areas.

Example 2

Increased molecular weight of levulinic acid dimers by second C-C coupling reactions with the metal oxide catalyst WO3 / ZrO2

The performance of the WO3 / ZrO2 catalyst was evaluated in a reactor test cycle with a starting material comprising 43 parts by weight of levulinic acid and 53 parts by weight of levulinic acid dimers and 2 parts by weight of acid oligomers. levulinic.

The starting material was obtained in the same way as in Example 1.

The second DC coupling reactions for the starting material were carried out in a continuous tubular fixed-bed microreactor at temperatures ranging from about 200 ° C to about 270 ° C and under a pressure of about 20 bar (2 MPa), using an hourly and mass-based space velocity (WHSV) of 0.5 h-1. Reactions were carried out with a stream of nitrogen (3 l / h) at temperatures of 240 ° C and with a stream of hydrogen (3 l / h) at temperatures above 240 ° C. WHSV was calculated from the amount of monomers, dimers, and oligomers (= liquid starting material) fed into the reaction vessel. For the reactions at different conditions, the amount of gas formed was determined from the liquid yield (gas = 100 - liquid product). The liquid product consists of the organic phase that includes the water formed during the reaction.

The quantitative amount of LA (levulinic acid) in the liquid product was determined by HPLC analysis. The relative amount of dimers and oligomers in the organic phase was obtained from GPC chromatograms. The composition of the organic phase, - including unreacted LA, was calculated with respect to the liquid product.

The composition of the organic phase was determined by GPC (area%).

Product yield and liquid phase compositions for the conversion of levulinic acid dimers on the WO3 / ZrO2 catalyst system into a stream of nitrogen and hydrogen are presented in Tables 4 and 5.

T l 4. niinrrn imi nrnl liz r W Zr 2.

The liquid phase contains organic oxygenates (= organic phase) and water. The amount of water in the liquid phase was not determined.

Table 5. Distribution of products in the liquid phase with the WO ³ / ZrO ² catalyst determined according to the areas of li P.

Example 3

Increased molecular weight of levulinic acid dimers by thermal C-C coupling reactions

Levulinic acid oligomers were produced by subjecting the same starting material used in Examples 1 and 2 to thermal C-C coupling reactions at temperatures above 200 ° C and in the absence of catalyst.

Thermal C-C coupling reactions for the starting material were carried out in a continuous tubular reactor at temperatures from about 220 ° C to about 250 ° C and under a pressure of about 2 bar (0.2 MPa). Reactions were carried out in 10 l / h of helium, nitrogen or hydrogen stream and also without any gas stream.

For the reactions at different conditions, the amount of gas formed was determined from the liquid yield (gas = 100 - liquid product). The liquid product consists of the organic phase that includes the water formed during the reaction.

The quantitative amount of LA (levulinic acid) in the liquid product was determined by HPLC analysis. The relative amount of dimers and oligomers in the organic phase was obtained from GPC chromatograms. The composition of the organic phase, including the unreacted LA, was calculated with respect to the liquid product.

Product yield and liquid phase compositions for conversion of levulinic acid dimers with thermal C-C coupling reactions are presented in Tables 6 and 7.

Table 6. C niinrrn imi nrnlrinl mi n -C thermal.

Table 7. Distribution of product in the liquid phase with the thermal DC coupling reactions determined nlrli P.

In none of the experiments of Examples 1 to 3, a significant degree of coking or tar formation was recognized after 40 days of continuous reaction. Additionally, from the above results, it can be confirmed that the oligomerization of dimeric keto acids produced at low temperature from keto acid monomers occurs at temperatures of and above 200 ° C. The resulting products have a suitable molecular weight distribution for further conversion to fuel or oil-based components and / or chemicals.

Claims (14)

1. A method of increasing the molecular weight of a keto acid, the method comprising the steps of providing a reactor with a raw material comprising at least one keto acid represented by Scheme 1 below and subjecting the raw material to a first reaction or reaction of CC coupling in the presence of an ion exchange resin catalyst to produce at least one dimeric keto acid, providing a reactor with a starting material comprising the at least one dimeric keto acid, subjecting the starting material to a second reaction or coupling reactions CC at a temperature of at least 200 ° C;

Scheme 1 where, in Scheme 1, n and m are integers each independently selected from each other from the list consisting of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. 2. The method according to claim 1, wherein the at least one dimeric keto acid is a dimer of a Y-keto acid, preferably a dimer of levulinic acid; me wherein the content of the at least one dimeric keto acid in the starting material is at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight, even more preferably at least the 55% by weight, and even more preferably at least 60% by weight. 3. The method according to claims 1 or 2, wherein the first and second C-C coupling reactions are carried out in a first and a second reactor, respectively. The method according to any one of claims 1 to 3, wherein the water content in the starting material is less than 15.0% by weight, preferably, less than 10.0% by weight, more preferably less than 5.0% by weight. 5. The method according to any one of claims 1 to 4, wherein the at least one keto acid in the raw material is a Y-keto acid, preferably levulinic acid (m = 2, n = 0). The method according to any one of claims 1 to 5, wherein the average pore diameter of the ion exchange resin catalyst is in the range of 150-300A, preferably 200-250A; and / or wherein the first C-C coupling reaction (s) are performed at a temperature in the range of 100-190 ° C, preferably 120-160 ° C, more preferably 120-140 ° C. The method according to any one of claims 1 to 6, wherein the raw material is subjected to the first reaction or CC coupling reactions in the presence of hydrogen, wherein the ion exchange resin catalyst preferably comprises the minus one hydrogenation metal selected from Group VIII of the Periodic Table of the Elements, preferably Co, Ni, Ru, Rh, Pd and Pt, more preferably Pd. The method according to any one of claims 1 to 7, wherein the starting material is subjected to the second C-C coupling reactions in the absence of catalyst. The method according to any one of claims 1 to 7, wherein the starting material is subjected to the second reaction or CC coupling reactions in the presence of a solid metal oxide catalyst system comprising a first metal oxide and the second metal oxide. 10. The method according to claim 9, wherein the catalyst system has a specific surface area of 10 to 500 m2 / g; me wherein the solid catalyst system comprises a mixture in which the first metal oxide is supported on the second metal oxide; me wherein the surface density of the metal atoms of the first metal oxide supported on the second metal oxide is 0.5 to 20 metal atoms / nm2; me wherein the first metal oxide comprises an oxide of one of K, Li, Be, B, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn , Br, Sr, Y, Zr, Nb, Mo, Ba, W, Pb, Bi, La, Ce, Th and the second metal oxide comprises one of K, Li, Be, B, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Sr, Y, Zr, Nb, Mo, Ba, W, Pb, Bi, La, Ce, Th, or a combination thereof, the first metal oxide not being the same as the second metal oxide; and / or wherein the first metal oxide comprises a potassium oxide and the second metal oxide comprises a titanium oxide, or the first metal oxide comprises a tungsten or cerium oxide and the second metal oxide comprises a zirconium oxide, titanium , silicon, vanadium or chromium, preferably a zirconium or titanium oxide; me wherein the content of the first metal oxide of the catalyst system is from 1.0 to 40.0% by weight, preferably from 2.0 to 30.0% by weight, more preferably from 13.0 to 30.0% in weight, calculated on the weight of metal oxide with respect to the total mass of the catalyst. The method according to any one of claims 1 to 10, wherein the starting material further comprises at least one keto acid, preferably a Y-keto acid, more preferably levulinic acid. 12. The method according to claim 11, wherein the content of the at least one keto acid in the starting material is at least 1.0% by weight, preferably at least 5.0% by weight, more preferably at least 10.0% by weight, or at least 30.0% by weight; me wherein the weight ratio of the at least one keto acid contained in the at least one dimeric keto acid contained in the starting material [keto acid: dimeric keto acid] is in the range of 1: 5 to 10: 1, preferably 1: 3 to 5: 1. 13. The method according to any one of claims 1 to 12, wherein the starting material is introduced into the reactor in liquid phase; me wherein the second CC coupling reaction or reactions are performed at a temperature in the range of 200-400 ° C, preferably 210-300 ° C, more preferably 220-280 ° C, and most preferably 220 -260 ° C; me wherein the second CC coupling reaction or reactions are carried out at a pressure in the range of 0.5-150 bar (0.05-15 MPa), preferably 1.0-50 bar (0.1-5 MPa), more preferably 1.0 20 bar (0.1-2 MPa); me wherein the second CC coupling reaction (s) are performed at a space velocity based on time and mass (kg starting material / kg catalyst * h) in the range of 0.05 Ir1 to 2.0h-1, preferably from 0.1 h-1 to 1.8 h-1, more preferably from 0.2 Ir1 to 1.5 h-1, most preferably from 0.25 Ir1 to 1.25 h-1; and / or wherein the starting material comprises at least one of 4-hydroxy-4-methyl-6-oxononanodioic acid, 3-acetyl-4-hydroxy-4-methylheptanedioic acid, 5- (2-methyl-5-acid -oxotetrahydrofuran-2-yl) -4-oxopentanoic acid, (E) -4-methyl-6-oxonon-4-enodioic acid, 4-hydroxy-6-methylnonanodioic acid, (E) -6-hydroxy-4-methylnon acid -4-enodioic, (Z) -3-acetyl-4-methylhept-3-enodioic acid, 3- (3-acetyl-2-methyl-5-oxotetrahydrofuran-2-yl) propanoic acid, (Z) -3 acid -1 (1-hydroxyethyl) -4-methylhept-3-enodioic and 3- (1-hydroxyethyl) -4-methylheptanedioic acid. 14. A method of producing hydrocarbons, the method comprising steps for increasing the molecular weight of a keto acid represented by Scheme 1 below using the method according to any of claims 1 to 13 to obtain a reaction product and subjecting the product to reaction to a hydrodeoxygenation step and, optionally, to an isomerization step;

Scheme 1 where, in Scheme 1, n and m are integers each independently selected from each other from the list consisting of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.